A device to device proximity service (Device to Device Proximity Service, D2D ProSe for short) already becomes a research subject of a 3rd Generation Partnership Project (The 3rd Generation Partnership, 3GPP) Long Term Evolution (Long Term Evolution, LTE) system Rel.12 system.
Generally, in a discovery process in a direct communication process and the direct communication process, user equipment adjusts, according to a timing advance configured by a base station, times for sending a signal and receiving a signal. However, because user equipment in an idle state cannot acquire the timing advance configured by the base station, a time for the user equipment to receive a signal is inaccurate, which may cause incompleteness of received data.